Quote:
Originally Posted by zkv476
When I run A/C and the compressor kicks in at idle the RPMs will dip a little and it does make the feeling of engine lugging. I believe it's completely normal, it's just spinning up the compressor from a dead stop at idle RPMs where there's little available torque. If you want to see if that's what's causing your exact noise, warm up the car fully (so the RPMs will idle normally since they idle higher when cold), park, and hit the A/C switch and turn the temp all the way down to force the compressor on. See if that replicates your sound.
|
I haven't yet been able to witness the RPMs dip when the compressor kicks in (my eyes are usually on the road not the tachometer whenever I hear the rattle), nor have I been able to purposefully cause the rattling sound by switching on the A/C while in idle. Maybe it will help if I turn the thermostat down to LO before I turn the A/C off, wait a while and let the car warm up, and then turn it back on while in idle. I've never heard the rattle while idling at a dead stop though, it only happens around 5 to 35mph. Sometimes its loud, sometimes it is very quiet or barely audible.